lol...come on, man. People have always associated mental illness (or worse, Satanic influence, example to follow) with things they don't understand. This one is going to ring true with some of our more senior members, I'm sure...my 90 year old grandmother was beaten repeatedly in school, to the point where she had to train herself to rework her brain to be something she's not.
Her crime: She was LEFT HANDED. Traditional wisdom stated that "left-hand-ism" was not only a sign of mental illness, but also a sign of demonic influence.
The implications of genetic links to transgenderism essentially means that rather than their reaction being a mentally ill response to being a gender they would, for "crazy reasons", rather not be, it is a perfectly mentally healthy reaction to a biological ailment of having their gender misaligned to their healthy, psychological, natural identity.
Don't believe me? Let me just ask you this... After a rough night of drinking, you find that someone has performed a gender reassignment surgery on you. Do the parts dictate the identity, and you finish your life as a woman, or do you go under the knife again to get your male bits back? As much as you are who you are, they are who they are.
And as someone who suffers from General Anxiety Disorder myself, I'm pretty over the whole notion that things people are afraid of or don't like get classified as mental illness by default, especially when our knowledge has advanced past the wisdom of 50 years ago, and we know better, as is the case here. In direct juxtaposition to your stance on mental illness not being an insult, I find that calling everything mental illness not only stigmatizes the person being accused of being "crazy", but it also further stigmatizes people with actual mental illness.
At the end of the day, sure, this is a debate site. But we also spend a lot of time together, and even amongst differing opinions we become friendly, if not friends. No one takes the skulls of their enemies home at the end of the day. Therefore I think it's appropriate to show a little bit of class and empathy when discussing these subjects, the more personal ones that impact us on a deep level. That's just my opinion, of course...for whatever it's worth.